Pencil sharpener

ABSTRACT

An improved pencil sharpener is provided which includes a container having a pencil-receiving channel extending from the exterior surface of the container into the interior thereof. A plurality of opposed spaced cutting blades are pivotally secured in the container with the pivot point adjacent the outer end of the channel and also of the blade. The blades are secured against rotation around their longitudinal axes. Preferably, the blades are generally wedge-shaped in side configuration, each being wider at its inner end and each with a cutting surface urged toward the cutting surface of the other blades by a resilient biasing means, such as a spring. Each blade has a sharp point along its cutting surface adjacent its inner end, which point is adapted to non-releasably engage a pencil when the latter is retracted or withdrawn along the channel from an interior location beyond said point. The sharpener is particularly adapted for use with carpenters&#39;&#39; pencils and the like.

United States Patent [191 Jones Dec.3,1974

1 PENCIL SHARPENER [22] Filed: Oct. 15, 1973 [21] Appl. No.: 406,200

[52] US. Cl. 145/31, 145/38 [51] Int. Cl B431 23/06 [58] Field of Search 145/3.1, 3.2', 3.3, 3.31, 145/3.4, 3.5, 3.6, 3.61, 3.8

[56] References Cited UNITED STATES PATENTS 194,525 8/1877 McLane 145/3.l 716,732 12/1902 Mead 145/3.8 841,391 1/1907 Hall 145/31 969,323 9/1910 Anderson 145/36 1,531,738 3/1925 Davis 145/331 1,775,601 '9/1930 Rew 145/3.8 2,236,979 4/1941 Troeber 145/35 2,982,253 5/1961 Herbold 145/38 FOREIGN PATENTS OR APPLICATIO NS 5,912 5/1886 Great Britain l45/3.8 4,019 3/1888 Great Britain... 145/331 116,617

6/1946 Sweden l45/3.8

, j 44 4o 22 1e Primary Examiner-Al Lawrence Smith Assistant Examiner.l. T. Zatarga Attorney, Agent, or Firm-John J. Posta, Jr.

[ 5 7] ABSTRACT An improved pencil sharpener is provided which includes a container having a pencil-receiving channel extending from the exterior surface of the container into the interior thereof. A plurality of opposed spaced cutting bladesv are pivotally secured in the container with the pivot point adjacent the outer end of the channel and also of the blade. The blades are secured against rotation around their longitudinal axes. Preferably, the blades are generally wedge-shaped in side configuration, each being wider at its inner end and each with a cutting surface urged toward the cutting surface of the other blades by a resilient biasing means, such as a spring. Each blade has a sharp point along its cutting surface adjacent its inner end, which point is adapted to non-releasably engage a pencil when the latter is retracted or withdrawn along the channel from an interior location beyond said point. The sharpener is particularly adapted for use with carpenters pencils and the like.

1 Claim, 4 Drawing Figures BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to sharpening means and more particularly to improved pencil sharpeners.

2. Description of Prior Art Hand held pencil sharpeners usually comprise a casing having a tapered pencil-receiving channel along which are disposed one or more fixed cutting blades. A pencil is sharpenedby feeding it gradually into the channel while rotating it or the casing to cause the blades to progressively peel a continuous layer of the pencil cover from the latter to expose the pencil lead and fix a point on the lead. Since the blades follow the taper of the channel, the pencil cover is removed on the same taper.

While the described hand held sharpeners are suitable for use with cylindrical pencilsor those having a considerable number of contiguous sides, they do not function satisfactorily with pencils such as carpenters pencils which are square or rectangular in crosssection, or pencils which have unusual shapes, e.g., are oval or the like. The same deficiencies are also encountered with conventional fixed model pencil sharpeners. All are adapted for use only with pencils which are round or essentially round in cross-section. Such fixed model pencil sharpeners are operated by inserting the pencil in the round diameter channel provided in the sharpener, after which a handle is turned to rotate the fixed cutting blades around the pencil while the latter is kept from rotating.

Accordingly, a need has arisen for an efficient, simple, relatively inexpensive, durable pencil sharpener capable of easily sharpening pencils of any crosssectional configuration, including those of square and rectangular cross-section such as carpenters pencils. Preferably, such a sharpener should operate with a minimum of effort, even with relatively large diameter pencils.

SUMMARY OF THE INVENTION The foregoing needs have been satisifed by the improved pencil sharpener of the present invention. The sharpener is constructed substantially as set forth in the' Abstract above. It has the advantage of being simple, easy to operate and durable, adapts to a wide range of diameters and configurations of pencils and eliminates rotation of the pencil and/or sharpener blades during sharpening. A minimum amount of effort is needed to cut through and sharpen even heavy duty pencils. The sharpener is equally adapted for hand held use and for fixed mounting hand use. It is easy to maintain, repair and replace. Further advantages are set forth in the following detailed description and accompanying drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a side elevation, partially in section, showing an additional operating mode of the device.

FIG. 4 is a schematic side elevation of a-second preferred embodiment of the pencil sharpener of the present invention, portions being broken away to illustrate certain internal features thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 The first preferred embodiment of the sharpener of the invention is schematically depicted in side elevation. Thus, a sharpener is shown which comprises a container or block 12. A pencil-receiving channel 14 extends from an exterior surface 16 of the sharpener 10 into the interior of the container 12. The channel 14 is defined by one or more internal walls 18 and can be of any suitable length, diameter and configuration. Preferably, the channel is straight and non-tapering and is of sufficient diameter to accommodate most sizes (diameters) of pencils, including carpenters pencils such as the pencil 20 shown in FIG. 1, which pencil is of square cross-section (not shown).

A plurality (in this instance two) of opposed spaced cutting blades 22 are pivotally secured in the container 12. Thus, each blade 22 is elongated and has a sharp cutting edge 24. Each blade 22 is aligned along a portion of the length of the channel 14. The outer end 26 of each blade, that is, the end nearest the outer end 28 of the channel is pivotally secured to that portion of the wall defining the channel 14 which is adjacent the outer end 28 of the channel 14. Such pivotal securement can be effected by pivot means, such as a pin' 30 running transversely through the outer end 26 of the blade 22 and connected to a bracket 32 secured to the wall 18. With such an arrangement, the inner end 34 of each blade 22 freely pivots toward the center of the channel 14 in a plane intersecting the channel 14. Each blade 22 is also secured against rotation about its longitudinal axis.

It will be noted that each blade 22 as shown in FIG. 1, is generally wedge-shaped in side elevation with the portion adjacent its inner end 34 wider than that at the opposite end 26. The cutting edge 24 of each blade 22 faces the channel 14 and also faces the cutting surface 24 of each other blade 22.

The depth of the channel 14 is regulated so that the end 42 of the pencil 20 to be cut can be inserted deep enough into the channel 14, i.e., to .a location which is past the cutting edge 24 of each blade 22. When the pencil 20 is inserted into the channel 14, it moves the blades 22 out of its way, causing them to pivot toward the wall 18 against the biasing force of a resilient biasing means disposed in the container. In the embodiment of FIG. 1, such biasing means comprises a compression spring 44 connected to each blade 22 adjacent the inner end of the surface 40 thereof and also appropriately connected to the wall 18.

Each spring 44 is selected so as to exert substantial biasing force. Thus, after the pencils cutting edge 24 is moved along the pencil 20 to a distance equal with that portion of the pencil 20 to be sharpened, the pencil 20 is then retracted along the channel towards the exterior surface 16 of the container 12. As the pencil 20 is retracted, each spring 44 urges its associated blade 22, particularly each cutting edge 24 into full contact with the outer surface of the pencil 20. The cutting edge 24 of each blade 22 digs into such surface, slicing at an angle down through the pencil 20 as it is retracted along the channel 14.

It will be noted that once each blade point 24 has dug in as described above, it is in non-retractable engagement with the pencil 20, i.e., it will not retract as long as the pencil 20 is not pushed forward into the channel 14. This positive engagement assures rapid and proper cutting of the pencil end 42 to sharpen thesame. As the retraction continues, the slice caused by the cutting edge 24 deepens.

After the pencil 20 is fully withdrawn, it is rotated sufficiently so that the next slices cut into the pencil 20 by the cutting edge 24 during withdrawal of the pencil 20 from the channel 14 will intersect the first slices and provide the required removal of the pencil end 42 at an angle so as to fully sharpen the same. Accordingly, the desired sharpening is effected merely by inserting the pencil 20 in the channel 14 to the required depth and then withdrawing it from the channel 14, rotating the pencil 20, and repeating the insertion and withdrawal, which only takes a matter of a few seconds, with minimal effort.

The described sharpening takes place regardless of the crosssectional configuration and size of the pencil, so long as the pencil 20 is small enough to fit into the channel 14. The channel 14 is straight-walled, rather than tapered, to provide maximum accommodation of pencil sizes and shapes, while the blades 22 depend at an angle into the channel 14 to accomplish the desired slicing of the pencil 20. The width of the blades 22 at ends 34 are at least as wide as the channel 14 to insure complete cutting across the width of pencil 20. This novel configuration provides quick-acting positive results.

Figure 4 The embodiment of the invention shown schematically in side elevation in FIG. 4 is identical with that of FIG. 1 except for the resilient biasing means. Accordingly, components identical to those of FIG. I bear the same numerals as in FIG. 1, but are succeeded by the letter a. Thus, sharpener a is provided which comprises a container 12a having a channel 14a, a pair of opposed wedge-shaped cutting blades 22a pivotally secured to the wall 18a defining the channel 140 and aligned along the length thereof The inner ends 34a of blades 22a and the cutting edges 24a are biased toward the center of the channel 14a and each other by biasing means in the form of a ring 46 of resilient elastomer, such as synthetic or natural rubber or the like, secured to the wall 180 defining the channel adjacent the inner end 34a of the blades 22a. In order to prevent the blade surface 40a from puncturing the ring 46, such surface is made rounded and curved, (not shown). The sharpener 10a functions in all respects similar to the sharpener l0 and has the same advantages.

Containers l2 and 12a can be made of any suitable material, such as wood, metal, plastic, fiberboard, etc. The blades 22 and 22a can be of steel, aluminum or other sharp edge-retaining metal or another suitable material. The springs 44 can be of any conventional materials, such as spring steel or the like.

It will be understood that various modifications and changes can be made in the sharpener of the invention and in its components. All such modifications and changes as are within the scope of the appended claims form part of the present invention.

What is claimed and desired to be secured by Letters Patent is:

1. An improved pencil sharpener for sharpening pencils or other instruments having various cross-sections, said sharpener comprising, in combination:

a container having a pair of upper and lower opposed, parallel panels and a pair of opposed, parallel side panels,

a first pin journalled in said side panels at the front thereof and adjacent to said upper panel,

a second pin journalled in said side panels at the front thereof and adjacent to said lower panels,

a first cutting blade pivotally secured'by and rotatable about said first pin, i

a second cutting blade pivotally secured by and rotatable about said second pin,

said first and second cutting blades having a cutting surface disposed on the end of each blade which is opposite the ends thereof secured to said pins,

said upper and lower panels havingre'cesses therein on the sides facing the interior of the container,

resilient biasing means disposed in each said recess adapted to contact the blade portion opposite said recess and to prevent rotation of said blades about said pins, v

a recess formed in the first and second cutting blades,

pencil from the container. 

1. An improved pencil sharpener for sharpening pencils or other instruments having various cross-sections, said sharpener comprising, in combination: a container having a pair of upper and lower opposed, parallel panels and a pair of opposed, parallel side panels, a first pin journalled in said side panels at the front thereof and adjacent to said upper panel, a second pin journalled in said side panels at the front thereof and adjacent to said lower panels, a first cutting blade pivotally secured by and rotatable about said first pin, a second cutting blade pivotally secured by and rotatable about said second pin, said first and second cutting blades having a cutting surface disposed on the end of each blade which is opposite the ends thereof secured to said pins, said upper and lower panels having recesses therein on the sides facing the interior of the container, resilient biasing means disposed in each said recess adapted to contact the blade portion opposite said recess and to prevent rotation of said blades about said pins, a recess formed in the first and second cutting blades, said resilient biasing means consisting of a pair of coil springs, said recesses in the upper and lower panels being round and adapted to receive one end of the coil springs, said recess in the cutting blades being round and adapted to receive the opposite end of the coil springs, whereby said coil springs are locked in place to prevent lateral movement thereof, but to allow freedom of compression and expansion of the coil springs in response to insertion or removal of a pencil from the container. 